1. Field of the Invention
The invention relates to a combined power plant installation configured as a single-shaft installation with common shafting, having a gas turbine, a steam turbine, the generator, which is located between them, and the associated auxiliary systems.
2. Discussion of Background
In such a combined power plant installation, known per se, the gas turbine and the steam turbine drive the common generator which is located between them. The machine foundation of this combined installation usually consists of a foundation slab in contact with the ground and of one or a plurality of platform units which are connected to the foundation slab by means of bearers. The machine components are secured on the upper slab, which has relieved regions for accommodating the machine components.
The configuration of the combined installation as a single-shaft installation means that only one generator is required. This reduces the costs and simplifies the operational procedure. Disadvantages do, however, occur when the rotor has to be taken out of the stator during maintenance or inspection work on the generator. Because of the design of the generator, the generator must be displaced sideways in order to permit the rotor to be withdrawn. For this purpose, the supply lines of the auxiliary systems, such as the hydrogen supply used for cooling, have to be disconnected and the generator has to be decoupled from the turbines and released from the upper slab. The generator is then usually raised by auxiliary means to the side where the maintenance work can be carried out. This leads to long dismantling times and reinstallation times, which in turn leads to a very time-intensive and therefore cost-intensive procedure. In the case of hydrogen-cooled generators, danger also arises due to the removal and reinstallation of the hydrogen supply because of leaks which may occur during the work and through which hydrogen can emerge.